I purchased five parking space locks for my private car park associated with my medical practice, which had been experiencing misuse by local residents. These parking space locks have effectively addressed the issue for me. They were straightforward to install, function flawlessly, and their size, which was initially a concern, proves to be an effective barrier against unauthorized parking. I highly recommend them and am considering purchasing additional units. For optimal effectiveness, I recommend a spacing of five to six feet between the two locks.